1. Field of the Invention
Embodiments of the present invention relate to a method and apparatus for avoiding a collision of a preamble in a base station, and more particularly, to a method and apparatus for avoiding a collision that may construct a random access preamble, which is a signature that may automatically obtain an uplink synchronization and a radio resource in an initial stage or in an operation, when a new base station is installed in a mobile communication system, without causing a collision between cells.
2. Description of the Related Art
In a mobile communication system, in particular, in a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, a terminal may generally perform a random access process for an access to a network. The terminal may perform the random access process to the network for initial access, handover, and the like.
The random access process may employ a contention scheme and a contention-free scheme. A difference between the contention scheme and the contention-free scheme lies in whether the terminal exclusively designates and uses a random access preamble. Specifically, in the case of the contention-free scheme, since a different preamble is used for a different terminal, a collision may not occur. In the case of the contention scheme, since the terminal uses a randomly selected preamble, at least two terminals may simultaneously use the same preamble and thus a collision may occur.
Even in the case of the contention-free scheme, when a large number of femtocells exist within a macro cell and a limited amount of preamble resources are used, a collision may occur due to the same code parameter, the time parameter, and the frequency parameter that are used between cells.